Fifth wheel



's. B. WlNN Sept. 3, 1940.

FIFTH WHEEL Filed Feb. 7, 1938 2 Sheets-Sheet l V Zhmentor I fie key 2? 7%)? p 1 0- I s. B. WINN 2,213,424

FIFTH WHEEL Filed Feb. 7, 1938 2 Sheets-Shet 2 3nnentor Patented Sept. 3, 1940 UNITED STATES "/FIFTH WHEEL Sidney B. Winn, Lapeer, Mich.

I Application February 2 Claims.

This invention relates to coupling means for tractors and semi-trailers. Coupling means as commonly used for this purpose embody a fifth wheel through which the weight of the forward end of the trailer is transmitted to the tractor and a king pin which constitutes the draft member between the tractor and trailer as well as a vertical pivot about which the trailer may swing relative to the tractors.

Coupling means of the character above referred tohave been standardized into two types.

The primary object of this invention is to provide a fifth wheel assembly which is adapted for coupling to trailers having either type of coupling mechanism. That is, the present fifth wheel assembly may be coupled to semi-trailers of the type embodying coupling members for engagement with a king pin carried by the tractor, andalso may be coupled to trailers of the type wherein the king pin is mounted on the trailer. To this end, the fifth wheel is constructed with a slot and coupling jaws adapted to receive and engage, respectively, a king pin mounted on the trailer. The fifth wheel also has a king pin mounted whereby it is housed beneath the top surfacethereof when it is used in conjunction with a semi-trailer having a king pin mounted thereon. When the tractor is used in conjunction with asemi-trailer having no king pin thereon, or in other words the other type, the king pin is moved to a position where it projects above the fifth wheel for cooperating with coupling jaws on the trailer.

Another object of the invention is to proing releasable means for holding the king pin' in its projected position.

7, 1938, Serial No. 189,117 (01. 280-334) With the above and other ends in view, the invention is more fully disclosed with reference to the accompanying drawings, in which Figure 1 is a plan-view of the fifth wheel;

Fig. 2 is a side elevation of the fifth wheel;

Fig. 3 is a section taken substantially on the line 3-3 of Fig. 1;

Fig. 4 is a section, similar to Fig. 3, illustrating the king pin in another position, and

Fig. 5 is a fragmental section taken on the line 5-5 of Fig. 3.

The brackets l are adapted to be mounted upon a tractor of the type commonly used in conjunction with semi-trailers. The brackets I carry horizontal pivots 2 upon which the fifth wheel. 3 is rockably supported. The fifth wheel 3 has a slot 4 for the reception of a king pin, and coupling jaws 5 normally held by Springs 6 in a position whereby they retain a king pin in the slot. In other words, the slot 4 and coupling jaws 5 constitute means for coupling a semi-trailer of the type wherein the king pin is mounted upon the trailer.

The coupling jaws 5 are so formed and pivoted that a king pin entering the slot brushes them aside, during the coupling function. To permit uncoupling, the jaws may be moved by links 7 which are adapted to be actuated by the hand lever 6.

Extending beneath the top surface of the fifth wheel is a well 9 in which a king pin it is slidably mounted. The wall of the well 9 is slotted at H and a. lever i2, pivoted at I3 on a bracket l4 carried by the wall formation, has its end I5 extended through the slot H and engaging the bottom of a groove I6 in the bottom of the king pin. The lever it has a depression I! therein adapted to be engaged by a ball l8. The ball I8 is mounted in a fitting l9 secured to the bracket l4 and is pressed by a spring 2i! into engagement with the lever l2.

When the fifth wheel 'is to be used in conjunction with a semi-trailer having the coupling jaws thereon, the lever I2 is manually moved to the position shown in Fig. 3 and causes the king pin to be elevated to a position where it projects above the top surface of the fifth wheel. When the lever I2 is thus moved the ball l8 engages the depression I1 and holds the leverl2 in a position maintaining the king pin elevated.

When the king pin is to be used in conjunci ti on with a semi-trailer having a king pin thereon, the lever 12 is manually moved to drop the king-pin to-the position shown.in Fig. 4. .The

king pin ordinarily will fall by force of gravity when it is unsupported by the lever [2, but in order to positively insure downward movement a pin 2! is provided in the king pin l0 extending across the groove l6 (Figures 3 to 5) and is engaged by the lever end l5 when the lever I2 is rocked to release it from the above described retaining means.

Although a specific embodiment of the invention has been illustrated and described it will be understood that various changes may be made within the scope'of the appended claims without departing from the spirit of the invention and such changes are contemplated.

What I claim is:

1. A fifth wheel for tractor-trailer vehicles comprising, a supporting member mounted on one of the vehicles for pivotal movement solely about an axis transversely of the vehicle, said member having an upper bearing surface and having a rearwardly facing slot at one side of said axis transversely thereto for receiving a king pin carried by the other vehicle, said supdetent for automatically holding said secondnamed king pin in its raised position.

2. In a fifth wheel member adapted for connecting with either a male or a female complementary fifth wheel, a king pin member reciprocably mounted in a recess extending below the upper periphery of said fifth wheel member, operating means projecting into said recess adapted to apply an elevating force to said king pin member, and means comprising a resiliently pressed detent for releasably holding said king pin member in its elevated position.

SIDNEY B. WINN. 

